+1-844-414-9223 For more information on American Airlines check-in as well as other relevant details, please refer to this blog from TheAirlinesInfo. To make a flight check-in: As early as 24 hours before the departure of your first flight, visit the website of your airline. Use your online account's confirmation number to check in. Additionally, you will be able to confirm your seating options and view your seats, provided the airlines enable it.